AIDS is a disorder that is still difficult to relieve and cure. Furthermore, the therapeutic treatments of AIDS currently available have the side effect of producing pain, and the pain induced includes nociceptive, neuropathic and idiopathic pain.
Several studies have been conducted in the use of botulinum toxin to attenuate or prevent various different disorders linked to HIV. These different uses of toxins have been described in the scientific and medical literature.
The use of botulinum toxin as an analgesic for the pain engendered by HIV itself is known from the scientific publication by Klein A. W. “The therapeutic potential of botulinum toxin”, Dermatologic Surgery, vol 30, no. 3, March 2004, pages 452-455.
The botulinum toxin used in the context of treating children suffering from HIV and concomitantly suffering from spasmodic paralysis and cerebral paralysis linked to HIV is described in the scientific publication of Noguera et al. “Botulinum toxin in the treatment of spasticity in HIV-infected children affected with progressive encephalopathy”, AIDS, vol. 18, no. 2, 2004, pages 352-353.
A study of the use of botulinum toxin in case of post-herpes neuralgia is described in the scientific publication of Liu HSU-TANG et al. “Botulinum toxin A relieved neuropathic pain in a case of post herpetic neuralgia” Pain Medicine, 2006, vol. 7, no. 1, Jan. 2006, pages 89-91.
The publication of Bach-Rojecky L et al. “Botulinum toxin type A in experimental neuropathic pain” Journal of Neural Transmission, vol. 112, no. 2, 1 Feb. 2005, pp. 215-219, reports the reduction of mechanical and thermal hyperalgesia as a result of using botulinum toxin in the particular context of an experiment carried out on rats, which had previously undergone partial transverse section of the sciatic nerve.
Amongst the most common types of pain in AIDS patients induced by anti-HIV drugs, abdominal pain, headaches, peripheral neuropathies, myalgia or arthralgia, can be mentioned, this list not being exhaustive.
Pain of these types affects many patients infected by HIV and chronically treated, for example for more than one year, by a chemical treatment to combat AIDS. Pain of this type should be distinguished from the pain induced by the virus itself. In fact, this pain is induced by the anti-HIV drug or drugs administered to the patients for the purpose of treating them.
The pain attributable to anti-HIV drugs has distinctive semiological characteristics. For example, peripheral neuropathy is characterized by continuous, diffuse pain with no mechanical or inflammatory rhythm and of a burning nature. Against this background of continuous pain other symptoms can occur, attacks of spontaneous pain such as stabbing or tingling pain and more particularly tingling in the extremities of members, or electrical discharges. The topography of these symptoms corresponds to a distribution compatible with a peripheral or central systematization, In other terms the topography of this neuropathic pain attributable to the anti-HIV drugs is independent of the topography of infection by the virus.
Among the known treatments for this pain, for example the administration of anticonvulsants, anti-depressants or opiates such as morphine can also be mentioned.
However, the use of the compounds currently available that make it possible to reduce the pain induced by treatment with anti-HIV drugs is not satisfactory because it requires the use of high doses of drugs or frequent re-administration of the drug with the possible development of resistance to the drug or habituation. In addition, these analgesic treatments can induce side effects, which occur in addition to those already induced by AIDS or by the treatment for it.
The impact of the suffering induced often has a devastating effect on the quality of life of the people affected and so it has become necessary to find another way to treat or prevent the pain induced by the anti-HIV drugs.
Thus the problem that the invention intended to solve is to find a new treatment for pain induced by the anti-HIV treatments, in particular antiretroviral treatments.